The Tropic of Cancer, which is also referred to as the Northern Tropic, is the most northerly circle of latitude on Earth at which the Sun can be directly overhead. This occurs on the June solstice, when the Northern Hemisphere is tilted toward the Sun to its maximum extent. It also reaches 90 degrees below the horizon at solar midnight on the December Solstice. Using a continuously updated formula, the circle is currently 23°26′10.3″ (or 23.43618°) north of the Equator.
Midnight sun is a natural phenomenon that occurs in the summer months in places north of the Arctic Circle or south of the Antarctic Circle, when the Sun remains visible at the local midnight. When midnight sun is seen in the Arctic, the Sun appears to move from left to right. In Antarctica, the equivalent apparent motion is from right to left. This occurs at latitudes from 65°44' to 90° north or south, and does not stop exactly at the Arctic Circle or the Antarctic Circle, due to refraction.
Twilight is light produced by sunlight scattering in the upper atmosphere, when the Sun is below the horizon, which illuminates the lower atmosphere and the Earth's surface. The word twilight can also refer to the periods of time when this illumination occurs.
Polar night is a phenomenon in the northernmost and southernmost regions of Earth where night lasts for more than 24 hours. This occurs only inside the polar circles. The opposite phenomenon, polar day, or midnight sun, occurs when the Sun remains above the horizon for more than 24 hours.
The 70th parallel north is a circle of latitude that is 70 degrees north of the Earth's equatorial plane, in the Arctic. It crosses the Atlantic Ocean, Europe, Asia and North America, and passes through some of the southern seas of the Arctic Ocean.
The 66th parallel north is a circle of latitude that is 66 degrees north of the Earth's equatorial plane, about 61 km south of the Arctic Circle. It crosses the Atlantic Ocean, Europe, Asia and North America.
The 68th parallel north is a circle of latitude that is 68 degrees north of the Earth's equatorial plane, in the Arctic. It crosses the Atlantic Ocean, Europe, Asia and North America.
The 69th parallel north is a circle of latitude that is 69 degrees north of the Earth's equatorial plane, in the Arctic. It crosses the Atlantic Ocean, Europe, Asia and North America, and passes through some of the southern seas of the Arctic Ocean.
The 71st parallel north is a circle of latitude that is 71 degrees north of the Earth's equatorial plane, in the Arctic. It crosses the Atlantic Ocean, Europe, Asia and North America, and passes through some of the southern seas of the Arctic Ocean.
The 73rd parallel north is a circle of latitude that is 73 degrees north of the Earth's equatorial plane, in the Arctic. It crosses the Atlantic Ocean, Europe, Asia, the Arctic Ocean and North America.
The 74th parallel north is a circle of latitude that is 74 degrees north of the Earth's equatorial plane, in the Arctic. It crosses the Atlantic Ocean, Europe, Asia, the Arctic Ocean, and North America.
The 75th parallel north is a circle of latitude that is 75 degrees north of the Earth's equatorial plane, in the Arctic. It crosses the Atlantic Ocean, Europe, Asia, the Arctic Ocean and North America.
The 76th parallel north is a circle of latitude that is 76 degrees north of the Earth's equatorial plane, in the Arctic. It crosses the Atlantic Ocean, Europe, Asia, the Arctic Ocean and North America.
The 77th parallel north is a circle of latitude that is 77 degrees north of the Earth's equatorial plane, in the Arctic. It crosses the Atlantic Ocean, Europe, Asia, the Arctic Ocean and North America. It is the northernmost integral parallel that passes through continental mainland.
The 78th parallel north is a circle of latitude that is 78 degrees north of the Earth's equatorial plane, in the Arctic. It crosses the Atlantic Ocean, Europe, Asia, the Arctic Ocean and North America. It is the southernmost integral parallel north that does not pass through any continental mainland.
The 79th parallel north is a circle of latitude that is 79 degrees north of the Earth's equatorial plane, in the Arctic. It crosses the Atlantic Ocean, Europe, Asia, the Arctic Ocean and North America.
The 80th parallel north is a circle of latitude that is 80 degrees north of the Earth's equatorial plane, and 10 degrees south of the North Pole, in the Arctic. It crosses the Atlantic Ocean, Europe, Asia, the Arctic Ocean and North America.
The 82nd parallel north is a circle of latitude that is 82 degrees north of the Earth's equatorial plane, in the Arctic. It passes through the Arctic Ocean and North America.
The 83rd parallel north is a circle of latitude that is 83 degrees north of the Earth's equatorial plane, in the Arctic. It passes through the Arctic Ocean and North America.
The 72nd parallel south is a circle of latitude that is 72 degrees south of the Earth's equatorial plane in the Antarctic. The parallel passes through the Southern Ocean and Antarctica.
